Article
Engineering, Multidisciplinary
Yan Shang, Zhuo Deng, Song Cen, Chen-Feng Li
Summary: This paper proposes a new penalty 20-node hexahedral element for size-dependent electromechanical analysis. The mechanical rotation is approximated using nodal rotation degrees of freedom, meeting the C-1 requirement and enhancing the interpolation for displacement test function. The stress trial function is formulated using normalized stress functions that satisfy the equilibrium and strain compatibility equations. The element has simple formulation and good numerical accuracy, as demonstrated by several benchmarks. Additionally, the influence of micro-inertia on electromechanical dynamic responses of flexoelectric solids at small scale is analyzed.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
(2023)
Article
Materials Science, Multidisciplinary
Olha Hrytsyna
Summary: The study applies the local gradient theory to the non-ferromagnetic electroelastic continuum, providing analytical solutions for an axisymmetric loaded hollow cylinder under different external loads, revealing the effects of charge load and pressure variations on material properties.
MATHEMATICS AND MECHANICS OF SOLIDS
(2022)
Article
Engineering, Multidisciplinary
M. C. Ray
Summary: This paper focuses on deriving exact solutions to investigate the effect of material length scale on the static responses of flexoelectric nanobeams under simply supported conditions. The derived solutions include displacements, stresses, electric displacements, and electric potential under closed and open circuit conditions. The paper determines the optimal value of the length parameter that makes the beam response independent of the couple stress effect when acting as an actuator. It also examines the impact of this length parameter on the beam's performance as an energy harvester.
APPLIED MATHEMATICAL MODELLING
(2022)
Article
Mechanics
Hamidreza Yademellat, Reza Ansari, Abolfazl Darvizeh, Jalal Torabi, Ali Zabihi
Summary: This study investigates the size-dependent dynamic pull-in instability of piezoelectrically and electrostatically actuated micro/nanobeams using the nonlocal strain gradient theory. The effects of flexoelectricity and piezoelectricity are considered, and various nonlinear forces are taken into account. The analysis method used in this study improves the reliability of the research model by comparing the results with existing literature.
MECHANICS BASED DESIGN OF STRUCTURES AND MACHINES
(2023)
Article
Materials Science, Multidisciplinary
S. M. H. Hosseini, Yaghoub Tadi Beni
Summary: In recent years, the investigation of flexoelectric and piezoelectric effects has been conducted separately in various studies. However, there is a need to study these effects simultaneously in a rotating microbeam while taking into consideration the size effects. Such investigation is crucial for better understanding the vibrational behavior of flexoelectric microstructures, identifying the flexoelectric and size-dependent effects on vibration frequency, and improving the design of microstructures.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2023)
Article
Physics, Applied
S. Baroudi, H. Samaali, F. Najar
Summary: The nonlinear vibration problem of a clamped-clamped monolithic piezoelectric flexoelectric beam as an energy harvester was investigated. The structure was found to be capable of harvesting energy, with the generated energy mainly attributed to the longitudinal potential variation and the transverse piezoelectric coefficient.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Mechanics
J. W. Xu, P. Wang, Z. H. Liu
Summary: This paper investigates the influence of flexoelectricity on the electromechanical coupling response of piezoelectric circular nanoplates with different electric boundary conditions. The results show that the flexoelectric effect has a more significant influence on the electrostatic responses than the piezoelectric effect at the nanoscale. The induced electric potential due to the flexoelectric effect may be helpful for sensing or energy harvesting designs.
Article
Multidisciplinary Sciences
Hanna Shevliakova, Semen O. Yesylevskyy, Ihor Kupchak, Galina Dovbeshko, Yunseok Kim, Anna N. Morozovska
Summary: The flexoelectric and piezoelectric properties of a bent 2H-MoS2 monolayer were studied, revealing that the flexoelectric effect dominates over the piezoelectric effect in both in-plane and out-of-plane directions. Additionally, the impact of strain gradients was found to induce a higher flexoelectric response compared to the piezoelectric reaction.
Article
Mathematics, Applied
Sonali Mondal, Sanjeev A. Sahu, Sonal Nirwal
Summary: This paper conducts a mathematical study on the reflection phenomenon of plane QP waves at a mechanically traction-free and dielectrically charge-free boundary surface of a pre-stressed rotating piezoelectric half-space. The effects of microstructure, micro-inertial, and strain gradient effects are considered. Five kinds of coupled elastic waves are generated due to the reflection phenomenon at the free surface. The reflection coefficients are numerically evaluated, and the discussion focuses on the influences of initial stresses, rotation, and flexoelectric coefficient on the reflection coefficients.
MATHEMATICAL METHODS IN THE APPLIED SCIENCES
(2022)
Article
Materials Science, Multidisciplinary
Ziwen Guo, Yilin Qu, Gongye Zhang, Changwen Mi
Summary: This paper studied the electromechanical fields in a composite plate with flexoelectric and piezomagnetic layers. It proposed governing equations and complete boundary conditions based on the couple stress theory, which characterized the size-dependent effects and flexoelectric effects. The paper provided constitutive relations for centrosymmetric cubic and hexagonal crystals. Numerical results showed that the deformation and electric potential distribution in the microplate can be effectively controlled by varying the magnitude of magnetic fields or flexoelectric coefficients. Additionally, adjusting the thickness ratio of the piezomagnetic and flexoelectric layers can also change the electromechanical properties.
MATHEMATICS AND MECHANICS OF SOLIDS
(2023)
Review
Engineering, Mechanical
Dongxia Tian, Dae-Yong Jeong, Zhenxiao Fu, Baojin Chu
Summary: This review summarizes the flexoelectric effect in ferroelectric materials, including measurement methods, theoretical studies, and the scaling effect. The review highlights the potential applications of the flexoelectric effect in sensors, actuators, and transducers.
Article
Chemistry, Multidisciplinary
Hui Ji, Shuwen Zhang, Kaiyuan Liu, Tonghui Wu, Shuaijun Li, Hao Shen, Minglong Xu
Summary: Recent advancements in electromechanical coupling effects have led to the development of soft and stretchable electromechanical materials for biomimetic applications. In this work, researchers have reported a flexoelectric enhanced elastomer-based film (FEEF) with both high electromechanical capability and stretchability. By utilizing biaxial pre-stretch, crosslinking density, nanoparticle size, particle filling ratio, and electric field charging, the researchers were able to enhance the flexoelectricity of the FEEF by two orders of magnitude.
MATERIALS HORIZONS
(2022)
Article
Engineering, Multidisciplinary
Kaichun Li, Chengbin Du
Summary: This study presents a numerical framework to model the effect of surface tension on a flexoelectric energy harvesting system with liquid inclusions. The equivalent Young's modulus and Poisson's ratio of the liquid inclusions embedded in flexoelectric composites considering the surface tension are derived for the first time. The simulation results indicate that considering surface tension can significantly enhance the electromechanical coupling coefficient and energy conversion capability.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2024)
Article
Chemistry, Analytical
Yuhang Chen, Maomao Zhang, Yaxuan Su, Zhidong Zhou
Summary: The flexoelectric effect has a significant impact on the electro-mechanical coupling of micro-nano devices, particularly in functionally graded beams. This study investigates the mechanical and electrical properties of such beams under various electrical boundary conditions, highlighting the influences of flexoelectric effect, piezoelectric effect, and gradient distribution on their performance. The results show that nonuniform piezoelectricity and polarization direction play a leading role in induced electric potential, and flexoelectric effect dominates as beam thickness decreases.
Article
Mechanics
Zanhang He, Jianghong Xue, Sishi Yao, Yongfu Wu, Fei Xia
Summary: A modified first order shear deformation theory is proposed for laminated micro-nano plates with couple stress components involved, based on mechanics of composite materials and Koiter's theory. Governing equations with size-dependent effect are derived and applied to investigate the buckling and free vibration of laminated micro-nano plates. The proposed theory is validated and shown to be efficient and accurate through comparisons with existing models and ABAQUS analysis.
COMPOSITE STRUCTURES
(2021)
Article
Acoustics
Rasoul Bagheri, Yaghoub Tadi Beni
Summary: This study investigated the size-dependent nonlinear forced vibration of viscoelastic/flexoelectric nanobeams. By solving the governing equations with numerical methods, it was found that size effect and viscoelastic medium effect parameters can increase vibrational frequency, while increasing the length and thickness of nanobeams decreases the frequency. Additionally, an increase in flexoelectric effect results in higher amplitude of nonlinear oscillation.
JOURNAL OF VIBRATION AND CONTROL
(2021)
Article
Mechanics
Shahriar Dastjerdi, Yaghoub Tadi Beni, Mohammad Malikan
Summary: This article uses a highly efficient quasi-three-dimensional theory to study the nonlinear hygro-thermo-mechanical bending analysis of a very thick functionally graded material (FGM) rotating disk in a hygro-thermal environment considering porosity as a structural defect. Two applied quasi-three-dimensional displacement fields are assumed, taking into account the strain along the thickness which is not zero unlike most plate theories. By considering nonlinear strains and large deformations, more accurate results are obtained, and further study on the factors affecting the results is conducted.
MECHANICS BASED DESIGN OF STRUCTURES AND MACHINES
(2022)
Article
Thermodynamics
Jaber Alihemmati, Yaghoub Tadi Beni, Yaser Kiani
Summary: In this article, the Chebyshev collocation numerical method is developed for solving generalized thermoelasticity problems of the isotropic layer. The derived system of differential equations is then solved by the Wilson method to achieve the displacement and temperature and also stress at any location and time. The obtained results from the present article are compared with the same results in the open literature and a very close agreement is observed.
JOURNAL OF THERMAL STRESSES
(2021)
Article
Engineering, Chemical
Yaghoub Tadi Beni, Jaber Alihemmati
Summary: This paper analyzed the transient coupled heat and moisture transfer in cylindrical and cylindrical panels of porous medium using three-dimensional finite element methods. The study considered both DuFour and Soret effects, derived weak forms of the equations using the Galerkin method, and solved the obtained differential equations using the Runge-Kutta method. The results were compared with analytical solutions, showing good agreement and demonstrating the formulation's applicability for transient analysis in cylindrical geometries under various boundary conditions.
TRANSPORT IN POROUS MEDIA
(2022)
Article
Thermodynamics
Jaber Alihemmati, Yaghoub Tadi Beni, Yaser Kiani
Summary: This paper develops a Chebyshev collocation numerical method for solving generalized thermoelasticity problems of isotropic homogeneous two dimensional media. The results closely match the analytical results in the literature.
JOURNAL OF THERMAL STRESSES
(2021)
Article
Engineering, Civil
I. Karimipour, Y. Tadi Beni, Hadi Arvin, A. H. Akbarzadeh
Summary: This paper analyzes wave propagation in micro-torus structures with circular cross-sections using the modified couple stress theory (MCST). The MCST proves to be more effective in describing the dispersion of waves at higher frequencies within micro-tours structures compared to classical continuum theory. The findings can be applied for the design of various devices such as sensors, actuators, medical equipment, and nanoscale transistor channels.
THIN-WALLED STRUCTURES
(2021)
Article
Engineering, Civil
Hamid Reza Balali Dehkordi, Yaghoub Tadi Beni
Summary: This paper investigates the coupled bending and torsional vibration analysis of microbeams under axial force based on Timoshenko's beam theory. The motion equations of the system are established using the modified non-classic coupled stress theory and the Hamilton principle. The generalized differential quadratures method is used to solve the obtained set of differential equations. The results show excellent agreement with other researchers' results and provide insights into the influence of various factors on natural frequencies.
ARCHIVES OF CIVIL AND MECHANICAL ENGINEERING
(2022)
Article
Physics, Multidisciplinary
Yaghoub Tadi Beni
Summary: In this study, torsional wave propagation in functionally graded flexoelectric micro/nano tubes was investigated and the governing coupling equations were derived. The dispersion phenomenon was observed, and the effects of flexoelectricity, micro inertia, and size on predicting actual torsional wave behavior in micro/nanotubes were studied.
WAVES IN RANDOM AND COMPLEX MEDIA
(2022)
Article
Physics, Multidisciplinary
Jaber Alihemmati, Yaghoub Tadi Beni
Summary: The present work combines the Green-Lindsay thermoelasticity theory with the modified strain gradient continuum theory to study the thermoelastic properties of micro continuum bodies. The derived equations are then applied to a one-dimensional microlayer, and the effects of microscale parameters on its dynamic thermo-elastic response are investigated.
WAVES IN RANDOM AND COMPLEX MEDIA
(2022)
Article
Mechanics
Yaghoub Tadi Beni
Summary: The free vibration and static torsion of a coupling electromechanical flexoelectric micro/nanotube have been investigated using non-classical theory of continuum mechanics. The coupling governing equations and their formulation with classical and non-classical boundary conditions have been developed. The effects of mechanical and electrical size effect parameters on direct and reverse flexoelectric torsion have been studied, and the introduction of polarization as a new variable in the equations has been investigated. The results highlight the importance of polarization in simulating torsional electromechanical structures.
EUROPEAN JOURNAL OF MECHANICS A-SOLIDS
(2022)
Article
Materials Science, Multidisciplinary
Jaber Alihemmati, Yaghoub Tadi Beni
Summary: In this study, the general form of coupled thermoelasticity for microstructures is derived by combining the Lord-Shulman thermoelasticity theory with the modified strain gradient theory. The developed model is applied to a one-dimensional microlayer and the governing thermoelasticity equations are derived based on both theories. The effects of length scale parameters on displacement, stress, and temperature distribution are investigated using a consistent Chebyshev collocation method.
MECHANICS OF MATERIALS
(2022)
Article
Engineering, Civil
Asghar Faramarzi Babadi, Yaghoub Tadi Beni, Krzysztof Kamil Zur
Summary: This study investigates the coupling equations of motion for the static and dynamic responses of a multilayered composite shell, considering the flexoelectric effect. The results show that the flexoelectric phenomenon significantly affects the electro-mechanical behavior of structures at micro and nano scales.
THIN-WALLED STRUCTURES
(2022)
Article
Engineering, Civil
Hamid Reza Balali Dehkordi, Yaghoub Tadi Beni
Summary: This paper investigates the free vibration of a carbon nanotube-reinforced composite Timoshenko microbeam considering the effect of axial load and bending-torsion coupling. The microbeam properties are developed based on the micromechanical model concerning the extended rule of mixtures. The governing equations of motion are derived using the modified couple stress theory and Hamilton's principle. The effects of different parameters on the natural frequency are demonstrated through tables and diagrams, highlighting the significant effect of carbon nanotube volume fraction and the nonconformity between mass and elastic axes.
ARCHIVES OF CIVIL AND MECHANICAL ENGINEERING
(2023)
Article
Engineering, Civil
Yaghoub Tadi Beni
Summary: This study investigates electro-thermal bucking in flexoelectric microbeams, focusing on two specific types of buckling in microbeams that are essential for microstructures, which are more susceptible to electro-thermal buckling due to electric fields and high temperatures in their environments. Additionally, microstructures can exhibit flexoelectricity, highlighting the significance of studying electro-thermal buckling. The paper derives closed-form solutions for the governing equations of flexoelectric microbeams and explores various boundary conditions, pre-buckling and buckling modes. The study reveals the absence of buckling in certain boundary conditions and emphasizes the importance of electrical curvature in isotropic and homogeneous flexoelectric microbeams. Furthermore, the paper presents specific electro-thermal buckling results and the probability of buckling for particular boundary conditions.
INTERNATIONAL JOURNAL OF STRUCTURAL STABILITY AND DYNAMICS
(2023)
Article
Physics, Multidisciplinary
S. M. Fatemi Vanani, Y. Tadi Beni
Summary: This paper investigates the impact of surface roughness on the pull-in behavior of beam-type nano-actuator in the presence of intermolecular Van der Waals force. It is found that roughness on the fixed electrode leads to increased displacement and reduced pull-in voltage of the beam. Moreover, roughness decreases the critical intermolecular force in the absence of electrostatic force, while increasing the material length scale parameters enhances pull-in voltage and freestanding values, and the size effect parameter reduces end-of-beam displacement.
INDIAN JOURNAL OF PHYSICS
(2021)
